[ Eq(Derivative(x1, t), (1*k33*k21 + 1*k33*k22*x1 + (-1)*k33*k23*x2/(k2 + x2)*x1 + (-1)*k33*k24*x7/(k4 + x7)*x5/(k5 + x5)*x1)/k33),
  Eq(Derivative(x2, t), (1*k33*k25*x1**k7/(k8**k7 + x1**k7)*x7**k10/(k4**k10 + x7**k10)*x6 + (-1)*k33*k26*x2)/k33),
  Eq(Derivative(x3, t), (1*k33*k27*x2 + (-1)*k33*k28*x3)/k33),
  Eq(Derivative(x4, t), -1/1000*k34*(k29*x3**3/(k12**3 + x3**3)*x4**k18/(k19**k18 + x4**k18) - k30*x5/(k14 + x5))/k34),
  Eq(Derivative(x5, t), (1/100*k34*(k29*x3**3/(k12**3 + x3**3)*x4**k18/(k19**k18 + x4**k18) - k30*x5/(k14 + x5)) + -1/20*k33*k31*x5/(k16 + x5) + 1/20*k33*k32)/k33) ]